This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Gate valves are used in a wide variety of industries including oil and gas, power generation, food and beverage, water treatment, and the like. Gate valves include a gate that moves between an open and closed position to control the flow of fluid through the gate valve. In the open position, the gate's bore is aligned with the flow path, thereby allowing fluid to flow through the gate. To interrupt flow, the gate and, more importantly, the gate's bore is moved to the closed position, placing the gate's bore in an unaligned position with the flow path. Gate valves that have large bores (e.g., approximately 5 inches or greater) and/or that operate at higher pressures (e.g., approximately 10,000 psi or greater) generally seal only against one side of the gate. From time to time, operators of the gate may want to test the gate's seal from both sides. This testing can be more easily conducted if both sides of the gate valve are sealed. Unfortunately, sealing both sides of a large bore and/or high pressure gate valve often requires very high turning force to mechanically open and close the gate valve.